1. Field of the Invention
This invention relates to a novel catalyst and particularly to a novel reforming catalyst. It also relates to a method for producing the catalyst and to reforming operations employing the same.
2. Description of the Prior Art
Catalytic reforming is a well known petroleum refining procedure. Essentially, a naphtha feedstock is treated to improve the octane rating for use as a gasoline. A number of reactions occur in typical reforming. The naphthenic components are dehydroisomerized and dehydrogenated to aromatics. Paraffins are dehydrocyclized to naphthenes and aromatics; normal paraffins are isomerized to isoparaffins. The resulting product should be high in C.sub.5.sup.+ product (components having a boiling point of pentane or higher).
Catalysts containing platinum, such as platinum on alumina, are known and have been widely used in naphtha reforming. Catalysts containing platinum and tungsten on alumina by impregnation with water, benzene or ethyl alcohol solutions (U.S. Pat. No. 3,661,769) and platinum, iridium and tin on alumina or other porous carriers by impregnation with water, ether or alcohol solutions (U.S. Pat. No. 3,718,578) are also known. U.S. Pat. Nos. 3,528,768 and 3,630,966 have disclosed the use of dimethylsulfoxide to incorporate Group VIII and other metals with zeolites. Platinum-rhenium on alumina is another known commercial reforming catalyst (U.S. Pat. No. 3,558,479). Reforming catalysts are usually described as being selective, active and stable. Selectivity is the measure of the ability of a catalyst to produce aromatic compounds from naphthenes and paraffins; activity is the overall ability of a catalyst to convert the feedstock into C.sub.5.sup.+ product; catalyst stability enables the catalyst to remain selective and active over an extended period.
The catalysts of the present invention exhibit excellent properties in all of the aforesaid characteristics.